docs: def load_data(cls, relpath):
          """
          Load data from the following sources in order of priority:
  
          1. Filesystem
  
          :param relpath: path relative to "data_path"
          :return: str - data content
          """
          filepath = os.path.join(cls.data_path, relpath)
          with open(filepath) as fp:
              content = fp.read()
  
          return content